1. Field of the Invention (Technical Field)
The present invention relates to briquettes for use with barbecue cooking grills, particularly to briquettes for use with gas-fired grills.
2. Background Art
Recreational cooking on outdoor grills is rapidly increasing in popularity. Outdoor grilling, often called "barbecuing," involves the use of a heat source that cooks the food, and that preferably also imparts a grilled or "barbecue" flavor to the food. Outdoor cooking grills historically have used pre-formed charcoal briquettes, or wood coals from a hot fire, as a heat source. A disadvantage of conventional pre-formed charcoal briquettes or wood coals is the length of time required to heat the charcoal or coals to sufficient grilling temperature. Further, standard charcoal briquettes tend to "shed" or break apart, which renders them unsuitable for use in modern gas-fired grills, as explained in U.S. Pat. No. 4,787,914 to Crace.
Modern alternatives to historical cooking grills are gas and electric grills, which can obtain cooking temperature in a comparatively shorter time. The naked flame of a propane gas or other gas grill, however, often is an uneven or variable source of heat, sometimes resulting in less than satisfactory barbecuing results. In an effort to ameliorate the problem of uneven cooking, permanent or semi-permanent briquette substitutes, usually consisting of either naturally occurring lava-type stones or cemented clay briquettes, frequently are used with gas grills. Basalt cobbles or cemented clay briquettes promote uniform, consistent, heating of the food over a period of time. The gas-generated flame heats the rock or cement briquettes, which then in cooperation with the gas flame cook the food. As the food cooks, juices from the foods may fall upon the heated rocks or cement briquettes. The flavoring compounds in the juices are volatilized from the rocks or briquettes and are absorbed into the grilled foods. Known semi-permanent briquettes for use in gas fired grills commonly are composed of Portland cement, with various types of small aggregate. These semi-permanent briquettes tend to break down after several, sometimes numerous, uses, but offer the advantage of allowing admixtures (such as hickory chips, liquid flavorizing agents) with the briquette at the time of manufacture. Wood chips promote "flavorization" of the grilled food.
Natural lava rock cobbles or stones also are used in lieu of man-made briquettes. Lava cobbles (e.g. anywhere from about 2.5 cm to about 10.0 cm or even 15.0 cm mean diameter) are desired for their durability. Lava rock repeatedly absorbs and radiates large amounts of heat energy over many cooking cycles before breaking down. Also, lava rock generally absorbs and re-radiates thermal energy in a desirably uniform manner, compared to many other types of solids. But natural lava rock cobbles do not admit the use of admixtures such as wood chips or other flavorizers, and thus inhibit the chefs efforts to impart a "barbeque" flavor to the food.
Although gas and electric grills are extremely convenient in terms of preparation time, the rocks or cement briquettes, unlike conventional briquettes made from charcoal, do not impart a natural "smoked" or wood barbeque flavor to the food being cooked. Rather, any additional flavor is dependent upon the food itself, as juices drop onto the hot briquettes.
In U.S. Pat. No. 4,058,052, to Hart, aluminum briquettes having liquid retaining channels are described, which allow fat and juices of the food to form a char on the surface of the briquettes so as to transmit flavored vapors to the food being cooked. Unfortunately, the char layer is often difficult to produce and the amount and choice of flavor transmitted to the food is difficult to control. U.S. Pat. No. 4,857,074, to Crace, discloses the use of a noncombustible, permanent briquette saturated with a liquid smoke composition. As the gas or electric grill heats the briquettes, the liquid smoke is volatilized, and flavor and color from the liquid smoke are added to the grilled foods. After use, the briquettes can again be soaked with any commercially available liquid smoke composition and used as before. Unfortunately, the liquid smoke is a less-desirable substitute for genuine wood-flavored barbecue.
U.S. Pat. No. 2,341,377 to Hinderer, and U.S. Pat. No. 5,427,805 to Crace, suggest the inclusion of wood pellets or chips within artificially molded briquettes so that the pellets release aromatic flavoring particles when burned. U.S. Pat. Nos. 4,787,914 and 5,096,727 to Crace, are illustrative of other previous attempts to develop suitable briquettes for use in barbecue grilling. U.S. Pat. No. 4,102,653 to Simmons et al. also is instructive as to the state of barbecue grills and briquettes.
Nevertheless, there exists a need for a permanent or semi-permanent briquette that manifests all three advantages of a briquette optimally useful in electric, or especially gas-fired, grills--the advantages of durability (repeated use with minimal "shedding" or physical breakdown), uniform heating characteristics (such as that provided by lava rock), and the imparting of wood-like flavor to the food being cooked. Against this background, the present invention was developed.